Sixth Street Specialty Lending, Inc. (TSLX) Stock Analysis

Sixth Street Specialty Lending (TSLX) is an externally managed BDC focused on providing flexible, committed financing to U.S. middle/upper-middle-market companies. Since starting investing in 2011 through Q3-2025, it originated ~$51.8B and retained ~$11.6B historically before exits/repayments, with an institutional backbone via Sixth Street (> $125B AUM). The portfolio (FY2025 fair value ~$3.37B) is diversified across 108 companies plus structured credit, and is designed for capital preservation through senior secured lending (first-lien/unitranche dominant) while opportunistically using mezzanine, bonds, structured credit, and equity co-investments to enhance yield. Revenue is primarily cash interest (96.3% floating-rate, SOFR-linked), complemented by modest PIK and episodic fee income (OID, syndication/amendment fees, prepayment penalties). Underwriting targets EVs ~$50M to $1B+ and EBITDA $10M–$250M, with deal sizes typically $15M–$350M and capacity to lead up to $500M syndications.